Two 4 month old Pekins picking on a Rouen duckling

I need help. I have two female Pekins, pretty sure they're females, no drake feather on either, that are about 4-5 months old. I've had both of them since they were a couple of weeks old. Spend a lot of time with them outside. I've noticed that they have a tendency to "lunge" at one of my dogs or one of my chickens when they get a little close to me but nothing of real concern, sometimes the wife. Today I brought home what I believe is a Rouen duckling, I'm guessing 2-3 weeks old, and introduced the Pekins to it. They "lunged" and nipped at the duckling and then they, what appeared to be, tried to drown the duckling. The Pekins get close and they kinda shake, or vibrate their heads and then "lunge". I put lunge in parenthesis because it's kind of a head thrust followed with running at the victim. I'm new to ducks but I'm trying to learn everything I can.

Also, while I'm here, my chickens chase me when I walk outside. They run up, get real close and stop. I'll stop real quick then turn around and bend down. They don't run away but they won't let me pick them up. I'll actually run around the yard and they'll chase me for awhile. Is this normal or do I just have the oddest creatures ever?

You have to wait until the duckling is 12 weeks old or they will kill it. At 12 weeks you can slowly introduce them to each other, but be prepared to see some fighting until they have established the pecking order.

We're new to ducks and chickens as well, but my guess is your Pekins are not happy about having a new member of the family. They are attached to you and this duckling is an interloper for your affection and attention. Same reason why they don't want the chickens near you, your dog or your wife! Can you keep the Rouen separated, but visible to the ducks and chickens so they can get used to it being around? Also the duckling is much smaller than your Pekins. I would wait until he/she is larger before introducing them...we have a 10.5 w/o Rouen and they get very big, very fast. He is almost twice the size of my mallards of the same age.

Older ducklings and adult ducks do not do well with ducklings. Most likely they are going to kill your baby unless you separate them. Once they are all approximately the same size, you can introduce them and let them sort things out, but in the mean time you're going to have to keep the little one away from the big ones. Sorry!

Thank you everyone. The little one has actually started "chasing" the Pekins a little. I think it's just wanted to fit in. It automatically jumps to the back of the line. The Pekins stop, stare at it until it walks off. We take the duckling out about twice a day and let it walk around and the Pekins will walk up to it and peck a little but nothing too bad yet, plus I'm always right there. Handful, that's for sure.